1. Field of the Invention
The present invention relates to a scanning examination apparatus, lens unit, and objective-lens adaptor. This application is based on Japanese Patent Applications Nos. 2005-084262 and 2005-084263, the contents of which are incorporated herein by reference.
2. Description of Related Art
Known scanning examination apparatuses in the related art include, for example, scanning laser microscopes (for example, see Japanese Unexamined Patent Application Publication No. 2000-275529).
A scanning laser microscope two-dimensionally scans a specimen by imaging laser light emitted from a laser light source onto the specimen using an objective lens, via proximity galvanometer mirrors. By scanning the specimen with laser light in this way, the scanning laser microscope splits off fluorescence generated in the specimen and returning via the objective lens and the proximity galvanometer mirrors from the incident laser light and detects it.
Therefore, in such a scanning examination apparatus, there is a problem in that it is difficult to align the position of the optical axis of the objective lens and the site to be examined on the specimen.
More specifically, when examining the specimen using the scanning examination apparatus, in a preparation stage carried out before actual examination, the position of the objective lens is roughly aligned with the site to be examined on the specimen, and the objective lens is disposed opposite the specimen with a large gap provided therebetween as a working distance. However, in this preparation stage, where no light is emitted, the operator must instinctively perform alignment considering the shape of the specimen and the shape of the objective lens.
Furthermore, because the light radiated from the light source is two-dimensionally scanned on the specimen by the proximity galvanometer mirrors, even though light is emitted in the preparation stage, it is difficult to determine the optical axis position of the objective lens from the light spot, which is continually moving. It is particularly difficult to determine the position of the optical axis of the objective lens when the light from the light source is laser light. For example, when the wavelength of the laser light is not in the visible region, it is not possible to confirm the radiated region, similar to the above. Moreover, even if the wavelength of the laser light is in the visible region, it is difficult to perform alignment due to the dazzle effect peculiar to laser light. In addition, an operator should not directly observe the laser light irradiating the specimen.
In the related art, microscopes are used to perform magnified observation of specimens, such as biological specimens. A microscope objective lens unit attached to a microscope includes an infinity optical lens group formed of a plurality of lenses contained in a lens barrel that can be attached to and removed from the main body of the microscope (examination apparatus). With this microscope objective lens unit, a lens or flat plate at the extreme tip thereof is brought close to or in contact with the specimen to enable magnified observation of the specimen, which is disposed at the focal position (for example, see Japanese Unexamined Patent Application Publication No. 2005-031425).
However, in a standard microscope objective lens unit, the outer diameter of the lens barrel containing the lenses is large and is therefore not suitable for in-vivo examination of the conditions below the surface of a biological specimen, such as inside a laboratory animal or the like. Therefore, to observe the conditions below the surface of a biological specimen, it is first necessary to make an incision in the skin and muscular tissue of the laboratory animal, and then to make an incision in the surface of the target biological specimen, such as various internal organs, and to bring the end surface of the microscope objective lens unit into contact therewith. However, because the size of the microscope objective lens unit is large compared to a small laboratory animal, in order to observe the conditions below the surface of a biological specimen, it is necessary to make a large incision or a large hole in the specimen.
In such a case, since the region to be examined is directly behind the incision or hole in the surface of the specimen, the specimen may be significantly damaged by forming such an incision or hole, and therefore it is difficult to perform time-lapse observation over a long period of time. Since this method involves sewing up the region where the incision or hole is formed after examination and making another incision the next time examination is carried out, the biological specimen is inevitably damaged. Therefore, this method suffers from the disadvantage that it is difficult to examine the specimen under normal conditions over an extended period of time.